Sharpening method

ABSTRACT

A sharpening method according to which it is possible to sharpen both sides of a cutting edge while utilizing structure driven from a common source of rotational movement. A work-holder and grinding wheel are simultaneously driven from the common source of rotational movement. Work may be held by the work holder and sharpened at one side of a cutting edge with a hand-held sharpening tool, and then the other side of the cutting edge can be sharpened by the grinding wheel while the work is hand-held after being removed from the work-holder. However, these steps may be reversed with the work first being held against the grinding wheel and then being held by the work holder with the hand-held sharpening tool applied to the work. The grinding wheel and the work-holder are preferably fixed to a common drive shaft driven by a motor with the grinding wheel situated between the work-holder and the motor.

United States Patent [191 Lepaw [5 SHARPENING METHOD [76] Inventor: Marvin I. Lepaw, 358 S. Oyster Bay Rd., Hicksville, NY. 11803 [22] Filed: May 24, 1974 [21] Appl. No.: 473,309

[52] US. Cl 51/285; 51/3; 51/98 BS; 51/168; 51/237 R [51] Int. Cl. B24B l/00; B24B 3/40; B24B 3/60 [58] Field of Search 51/3, 72 R, 98 R, 98 BS, 51/168, 181 R, 161, 162, 204, 216 T, 217 T,

' 218 T, 225, 227 R, 237 R, 262 R, 281 R, 281

[ Sept. 23, 1975 Primary ExaminerDonald G. Kelly Attorney, Agent, or FirmSteinberg & Blake [57] 1 ABSTRACT A sharpening method according to which it is possible to sharpen both sides of a cutting edge while utilizing structure driven from a common source of rotational movement. A work-holder and grinding wheel are simultaneously driven from the common source of rotational movement. Work may be held by the work holder and sharpened at one side of a cutting edge with a hand-held sharpening tool, and then the other side of the cutting edge can be sharpened by the grinding wheel while the work is hand-held after being removed from the work holder. However, these steps may be reversed with the work first being held against the grinding wheel and then being held by the work holder with the'hand-held sharpening tool applied to the work. The grinding wheel and the work-holder are preferably fixed to a common drive shaft driven by a motor with the grinding wheel situated between the work-holder and the motor.

5 Claims, 6 Drawing Figures US Patent Sept. 23,1975

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IHIQIII SHARPENING METHOD BACKGROUND OF THE INVENTION The present invention relates to sharpening methods.

In particular, the present invention relates to a sharpening method which is especially suitable for sharpening the cutting edge of an instrument such as a biopsy punch.

As is well known, an instrument of this latter type requires an extremely sharp cutting edge. At the present time it is possible to attempt to maintain such a cutting edge in a good operating condition by applying a sharpening tool to the interior of the tubular punch so as to engage the inside of the cutting edge to sharpen the latter. However, such operations result in a jagged cutting edge which has undesirable burrs resulting from such sharpening operations. At the present time the instrument is used in this latter condition, which is highly unsatisfactory, or if attempts are made to eliminate the burrs and even to sharpen the cutting edge at the outside thereof, the latter operations can be carried out only with difficulty.

SUMMARY OF THE INVENTION It is accordingly a primary object of the present invention to provide a method which will avoid the above drawbacks.

In particular, it is an object of the present invention to provide a method and apparatus which will enable a cutting edge of an instrument to be sharpened on both sides in a simple convenient manner which will provide the best possible condition for the cutting edge.

According to the invention two sharpening steps are performed in any desired sequence. One of these sharpening steps involves rotating the work while sharpening one side of a cutting edge with a hand-held tool, and the other step involves holding the work while applying the other side of the cutting edge thereof to a rotating grinding wheel.

BRIEF DESCRIPTION OF DRAWINGS The invention is illustrated by way of example in the accompanying drawings which form part of this application and in which:

FIG. 1 shows in a side elevation one possible embodiment of a sharpening apparatus for carrying out the method according to the present invention;

FIG. 2A shows in a partly fragmentary side elevation part of the sharpening method of the present invention;

FIG. 2B further illustrates the part of the method shown in FIG. 2A;

FIG. 3 is an end view of the instrument shown in FIG. 2A, taken along line 33 of FIG. 2A in the direction of the arrows;

FIG. 4 is a fragmentary longitudinal sectional elevation of the instrument of FIG. 2A after one sharpening step has been performed; and

FIG. 5 is a longitudinal fragmentary sectional elevation of the instrument of FIG. 4 after a second sharpening operation has been performed to complete the sharpening of the instrument.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to FIG. 1, one possible embodiment of the present invention is illustrated therein. Thus, FIG. 1 illustrates a motor carried by a suitable base 12 and being capable of connection with a source of electrical energy through conductors 14. Thus the conductors 14 may terminate in a plug capable of being received by a wall outlet, or any desired source of electrical energy may be provided. The motor 10 is capable,

of being turned on and off by way of a switch 16.

The motor 10 has a rotary drive shaft 18 which rotates about its own axis when the motor 10 is energized. Thus through the drive shaft 18 there is provided a source of rotational movement.

A grinding wheel 20 is fixed to the shaft 18 for rotation therewith. This grinding wheel 20 is of a simple circular configuration, having the construction of a cylindrical block provided with an axial bore through which the shaft 18 extends. The shaft 18 fixedly carries a collar 22 against which the grinding wheel 20 is placed, with a washer 24 being situated on the opposite side of the grinding wheel. A nut 26 is carried by a threaded portion of the shaft 18 for clamping the grinding wheel 20 between the collar 22 and the washer 24, so that in this way the grinding wheel 20 is fixed to the shaft 18 for rotation therewith.

At its free end region 28 the drive shaft 18 is formed with a tapered bore receiving the tapered shank 30 of a work-holder in the form of a conventional drill chuck 32, for example. Thus the tapered shank 30 is simply received with a friction fit in the tapered bore at the free end region 28 of the shaft 18 so that the workholder formed by the chuck 32 will rotate together with the shaft 18. The chuck 32 includes, in a well known manner, a plurality of gripping jaws 34 capable of being moved into and out of gripping engagement with work which is to be sharpened by insertion of a rotary key in an opening such as the opening 36, with the teeth of the rotary key engaging the teeth 38 of a rotary ring 40 which when rotated in one direction will cause the jaws 34 to approach each other and when rotated in the opposite direction will cause the jaws 34 to move apart from each other and away from the axis of the shaft 18 toward and away from which the jaws 34 are movable in a well known manner.

The above-described structure may be used according to the method of the invention in a manner which is illustrated in FIGS. 2A-5. In the example illustrated the work 42 held by the jaws 34 takes the form of a biopsy punch having at its end 44 an endless cutting edge 46 which is situated, as illustrated in FIG. 2A, in a plane normal to the axis of the punch 42. The punch 42 will of course have its axis in coincidence with the axis of the shaft 18 when the punch 42 is gripped by the jaws 34 of the work holder 32. As is shown most clearly in FIG. 3, the endless cutting edge 46 includes an inner side 46a, an outer side 46b, and the extremity 46c formed by the intersection of the sides 46a and 46b of the cutting edge. It is of course important for such a biopsy punch to have a well sharpened cutting edge 46 so that it can be used properly, and it is to be understood that the wall of the tubular biopsy punch 42, at the region of cutting edge 46 is relatively thin so that the cutting edge is shown at an enlarged scale in FIG. 3 for the sake of clarity.

With the punch 42 held by the work holder 32 in the position shown in FIG. 2A, the motor 10 is turned on so that the punch 42 will rotate about its own axis, and now the operator can place in engagement with the inner side 46a of the cutting edge 46 a sharpening pencil or tool 48 in the form of a tapered soap stone grinding element. The left tapered end of the sharpening tool 48 is small enough to be received in the hollow interior of the punch 42, as shown in FIG. 28, so that the tool 48 will sharpen the inner side 46a of the sharpening edge, with the result that the structure will then have the condition which is shown in an exaggerated manner in FIG. 4.

Thus, as may be seen from FIG. 4, due to the operations performed with a sharpening tool 48 and due to the small thickness of the wall 44 of the punch 42, at the region of edge 46, the side 46:: of the cutting edge 46 will be properly sharpened, but the side 46b will have portions 46d which are deflected outwardly and which take the form of burrs and the like shown at an enlarged scale in FIG. 4.

At this stage of the method of the invention the motor is stopped and the instrument 42 is removed from the work-holder 32. Then, while the instrument is hand held it is placed at the outer side 4612 of the cutting edge 46 against the rotating grinding wheel 20, the motor being turned on after the work has been removed from the work-holder 32. Thus, by applying the work which has the condition shown in FIG. 4 against the rotating grinding wheel 20, it is possible to provide the instrument 42 at its cutting edge 46 with the properly sharpened outer side 46b intersecting the inner side 46a at the extremity 46c which thus achieves the proper cutting edge for the instrument 42. FIG. 5 illustrates the punch 42 in its completely sharpened condition. It will be noted from FIG. 5 that the illustrated punch has a transverse wall 41 formed with openings 43. Wall 44 is connected through reduced portion 52 and flange 50 to the remainder of the punch 42.

It is apparent that with the above-described method of the invention it is possible in an extremely convenient manner to sharpen the edge of an instrument such as the biopsy punch 42 in such a way that the cutting edge 46 will be smooth and sharp, while being completely free of any irregularities, burrs, or the like. Thus it is clear that at the stage of the operations illustrated in FIG. 4, after the sharpening of the inside edge 46a has been completed with the hand-held tool 48, the sharpening of the edge 46 is only partially complete, with the completion of the sharpening being carried out only after the instrument 42 is hand-held against the grinding wheel to provide the sharpening at the outside 46b of the cutting edge 46. Therefore both the work-holding means 32 as well as the grinding wheel 20 are required to complete the sharpening of the instrument.

Moreover, it is apparent that the two basic sharpening steps referred to above need not be performed in the above sequence. Thus, instead of first sharpening the inside 46a of the cutting edge 46 and then the outside 4612 thereof, it is equally possible first to apply the hand-held instrument 42 against the wheel 20 so as to sharpen first the outside 46b of the cutting edge, and then the instrument 42 may be placed in the chuck 32 so as to be held thereby with the final sharpening step being carried out by the hand-held tool 48. With this type of method the burrs or other irregularities, instead of being directed outwardly, as shown in FIG. 4, will be directed inwardly, and they will be removed while the inner side 46a of the cutting edge is sharpened by the hand-held sharpening tool 48.

Furthermore. the method may be carried out in such a way that the above two basic sharpening steps can be performed simultaneously. For example assuming that a plurality of instruments 42 are to be sharpened, it is possible for one individual to sharpen only the inner sides 46:! of the cutting edge 46 of successive instruments 42. As soon as this one individual completes his operations he delivers the partially sharpened instruments, having the condition shown in FIG. 4, to a second individual who then sharpens the instruments at the outer side 46b of the cutting edge 46. Thus, while sharpening of one side of the cutting edge is going forward with one instrument, sharpening of the other side of the cutting edge is going forward simultaneously with another instrument, so that in this way a high rate of production can be achieved with the single apparatus shown in FIG. 1 and with two operators simultaneously performing both of the above steps.

Furthermore, it is to be understood that while the method of the invention is particularly applicable for an instrument such as a biopsy punch, the method and apparatus are of course capable .of being used for sharpening other types of work. Thus any cutting edge, even of a solid punch, for example, which is sharpened with a hand-held sharpening tool while the work is held by the work-holder 32, can have its cutting properties improved if the edge is placed against the grinding wheel 20 to eliminate irregularities, burrs, or the like, so that the initially jagged cutting edge can be rendered smooth to achieve a highly effective cutting action.

What is claimed is:

1. In a sharpening method, performing simultaneously on a pair of instruments or in a given sequence on one instrument one step which includes simultaneously rotating from a common source of rotational movement a grinding wheel and a work-holder while sharpening with a hand-held sharpening tool one side of a cutting edge of an instrument held by and rotating with the work-holder, and another step which includes sharpening another side of the cutting edge of the instrument while the latter is hand-held and placed at said other side of said cutting edge thereof against said grinding wheel with the latter being rotated together with the work-holder from the common source of rotational movement.

2. In a method as recited in claim 1 and wherein said one step is carried out prior to said other step.

3. In a method as recited in claim 1 and wherein said other step is carried out prior to said one step.

4. In a method as recited in claim 1 and wherein said steps are performed simultaneously on a pair of instruments.

5. In a method as recited in claim 1 and wherein the instrument is a biopsy punch having at one end an endless cutting edge surrounding an axis of the punch, said one side of said cutting edge being situated along the inside of the punch and said other side of said cutting edge being situated along the outside of the punch. 

1. In a sharpening method, performing simultaneously on a pair of instruments or in a given sequence on one instrument one step which includes simultaneously rotating from a common source of rotational movement a grinding wheel and a work-holder while sharpening with a hand-held sharpening tool one side of a cutting edge of an instrument held by and rotating with the work-holder, and another step which includes sharpening another side of the cutting edge of the instrument while the latter is hand-held and placed at said other side of said cutting edge thereof against said grinding wheel with the latter being rotated together with the work-holder from the common source of rotational movement.
 2. In a method as recited in claim 1 and wherein said one step is carried out prior to said other step.
 3. In a method as recited in claim 1 and wherein said other step is carried out prior to said one step.
 4. In a method as recited in claim 1 and wherein said steps are performed simultaneously on a pair of instruments.
 5. In a method as recited in claim 1 and wherein the instrument is a biopsy punch having at one end an endless cutting edge surrounding an axis of the punch, said one side of said cutting edge being situated along the inside of the punch and said other side of said cutting edge being situated along the outside of the punch. 